One known waste storage device is disclosed in GB Patent No. 2206094 (incorporated herein by reference) and described here with reference to FIG. 1. The device is particularly useful for the storage for subsequent disposal of waste such as babies' nappies or other personal waste material. A plastics container 21 is formed with an internal flange 22 from which a cylinder 23 extends upwards. A pack consisting of a tubular core 1 inside a profusely circumferentially pleated length of flexible tubing 2 is located in the container 21 with the core 1 resting on the flange 22 and rotatable on the cylinder 23. To begin using the pack to form a series of packages of objects, which in this particular example will be considered to be babies' disposable nappies, the top of the flexible tubing 2 is pulled upwards and tied into a knot 24. This closed end can then form the bottom of a package to be formed along the length of part of the tubing. This is effected by pushing the closed end downwards inside the core 1 and cylinder 23 by the object to be packaged. As this is being done the flexible tubing 2 from the pleated length slides over the top edge 25 (FIG. 1) of the core 1 which is made sufficiently smooth to prevent the flexible tubing from being damaged. The core 1 may be approximately four inches (10.16 cm) diameter but, of course, the diameter of the flexible tubing 2 is substantially more than this.
When the object has been thrust well into the concentric core 1 and cylinder 23, the package is closed by twisting the flexible tubing 2 above the object as at 30 (FIG. 1). This is done by turning the core 1 with remaining pleated tubing thereon about the core axis. A unit 31 is formed for this purpose in that it has a depending annular flange 50 formed with an outer surface that is a taper fit in a frusto-conical inner surface 51 at the top of the core 1. The package is prevented from turning about the axis of the core during this manual twisting action by springs 52 fixed to the container 21 and projecting radially inwards to engage the package. These springs are equidistantly spaced round the container 21. Shallow grooves dividing upwardly extending ridges are formed on the frusto-conical inner surface 51 to stop slippage of the flexible tubing during the twisting operating.
By the aforesaid means, a series of connected closed packages 35 are formed and this can be continued until the pleated tubing 2 is exhausted. In the arrangement of FIG. 1 the packages collect in a bin portion 36 of the container closed at the bottom by a hinged base 53 normally held closed by a manually operable catch of suitable type. When it is desired to remove the packages from the bin portion 36 for transport to a waste disposal facility, the uppermost package is severed above its upper twisted closure 30 and the hinged base 53 opened for the removal of the packages through the end of the bin portion. Even if the twisted seals between the packages become loosened, the lid and the newly formed topmost twisted seal with prevent the escape of odours, vapours and gases to the ambient atmosphere. However, it has been found that when the tubing 2 is made of high density polyethylene the twisted joints remain remarkably tight
A development of this arrangement is disclosed in GB 2292725 (incorporated herein by reference) and described here with reference to FIG. 2. It will be seen that an outwardly flared funnel 12 having an inlet edge 15 is detachably connected to the top of the core 1 by a taper joint 16. The funnel improves the hygiene of the device yet further because the flexible tubing 2 is drawn from the pack as an object is pushed down, over the inlet edge 15 of the funnel 12 to present a fresh and hygienic layer of tubing in the flared part of the funnel. The funnel 12 is twisted to obtain the twisted closure 30. An alternative spring arrangement 14 is shown in FIG. 2 and described fully in GB 2292725.
GB 2206094 and GB2292725 both additionally disclose a cutting arrangement for severing the tubing when it is desired to remove the packages for disposal. Referring to FIG. 3, the severing means is incorporated in the unit 31 which is a bipartite unit comprising an outer ring 55 formed with a flange 50 that locks into the top of the core 1 or funnel 12 and a disc 56 which is freely rotatable in the ring 55. The disc 56 comprises a circular transparent sheet 57, through which the user can see the twisted flexible tubing, set in an angle section ring having a horizontal flange 58 and a vertical flange 59 (FIG. 1) located between narrow flanges inside the relatively stationary flange 50. In the angle of the ring 58,59 three finger pieces 60 are fixed 120° apart above the transparent sheet 57. A cutter unit 61 is fixed beneath the flange 58. This device has an upper arcuate part 62 and a lower tapered shoe 63 with a gap between them along the major portion of their length. Close to the closed termination of this gap a metal cutter blade 64 is fixed as close as possible to the relatively stationary flange 50 so that the blade is shrouded against doing any damage to a person's fingers when the lid 31 is removed. The predominant material for the lid may be plastics material or metal.
To operate the cutter unit 61, the disc 56 is turned by means of the finger pieces 60 or any other suitable finger pieces through a full revolution. In this movement the tapered shoe 63 pierces through the radially pleated taut portion 65 of the flexible tubing that flares outwards from the topmost twist 30 to the core 1. Further rotation of the disc 56 causes the cutter blade 64 to cut round the tubing material, cleanly separately the uppermost package from the flexible tubing remaining on the core 1. The cutter unit further includes a finger releasable detent operable at 120° intervals.
In a further improvement, WO99/39995 (incorporated herein by reference) describes a cutter of similar type to that described above with reference to FIG. 3 but formed intergrally with a hinged lid for a waste storage container. The hinged lid swings down to close the container and as a result the cutter automatically engages the tubing allowing a simplified cutting arrangement.
Various areas for further improvement exist in relation to the known devices. Twisting of the tubing is done manually and requires direct contact of the user's hands with the tubing which can be undesirable even with the funnel arrangement described above. The existing spring arrangement for holding the tubing against rotation in some instances provides insufficient user tactile feedback as to whether a package is securely held by the springs. In addition the packaging can be held unevenly tightly around its circumference as a result of which the cutting operation can be impaired. Furthermore packages suspended beneath the springs can untwist, removing the individual seals between packages.
With the existing cutter design it can be unclear whether a full cut has been achieved without repeated checking and there is also a risk that the cutter will be rotated in the wrong direction.
With regard to the cassette design it is found that a range of different cassettes are required for different container formats. In addition it is desirable to minimise the resistance to rotation of the cassette.
The invention is set out in the attached claims.